Biomedical subjects

Mohammad Farooq

Publications and source records attributed to Mohammad Farooq.

4 recordsLinked to original sources

PubMed2003

Growth promotion of HepG2 hepatoma cells by antisense-mediated knockdown of glypican-3 is independent of insulin-like growth factor 2 signaling.

Glypican-3 (GPC3) encodes a cell-surface heparan- sulfate proteoglycan and its expression is frequently silenced in ovarian cancer, mesotheliomas, and breast cancer cell lines and ectopic expression of GPC3 inhibited the growth of these cells, suggesting that GPC3 plays a negative role in cell proliferation. In contrast, up-regulation of GPC3 is often observed in hepatoma, neuroblastoma, and Wilms' tumor. Whether GPC3 plays the same growth inhibitory role in these tumors remains to be studied. Here we report that antisense-mediated knockdown of GPC3 in the HepG2 hepatoma cells significantly promotes the growth of hepatoma cells. In addition, we show that this growth promotion is independent of insulin-like growth factor 2 (IGF2) signaling. Our data suggest that GPC3 plays a growth-suppressing role in hepatoma and provide cell biological evidence inconsistent with the hypothesis that GPC3 acts as a growth suppressor by downregulating IGF2.

Carcinoma, Hepatocellular↗

PubMed2003

Blocking endogenous glypican-3 expression releases Hep 3B cells from G1 arrest.

Glypican-3 (GPC3) encodes a cell-surface heparan-sulfate proteoglycan mutated in type 1 Simpson-Golabi-Behmel syndrome (SGBS1), an X-linked overgrowth syndrome. The phenotype of SGBS1 patients and of GPC3 knockout mice suggests that GPC3 plays a negative role in cell proliferation, and an apoptosis-inducing role in specific tissues. Ectopic expression of GPC3 in some cell lines has supported the idea that GPC3 inhibits cell growth. Here we report that blocking endogenous GPC3 expression with an antisense transcript promotes the growth of Hep G2 and Hep 3B hepatoma cell lines. Moreover, antisense inhibition releases Hep 3B cells from cell cycle arrest. Hence, our data further support the notion that GPC3 is an inhibitor of cell proliferation and demonstrate that it modulates cell cycle progression.

Animals↗

PubMed2003

Glypican-3 is overexpressed in human hepatocellular carcinoma.

To identify candidate genes that could be used as diagnostic and therapeutic targets for hepatocellular carcinoma (HCC), we searched for the genes that are overexpressed in HCC by combining representational difference analysis and microarray. Genes such as glypican-3 (GPC3), insulin-like growth factor 2, long-chain fatty-acid-coenzyme A ligase 4, farnesyl diphosphate synthase were frequently identified in our screening. Northern blot analysis with these four genes confirmed their overexpression in HCC. Among them we found that GPC3 transcript is upregulated in six out of seven cases of HCC. Immunoblot and immunohistochemical staining using polyclonal anti-GPC3 antibodies further confirmed that GPC3 protein is indeed increased in HCC tumor samples. We also found that GPC3 is secreted into culture media from cell lines derived from HCC. We conclude that GPC3 is a good molecular marker for HCC.

Biomarkers, Tumor↗

PubMed2002

Gene expression profile analysis in human hepatocellular carcinoma by cDNA microarray.

We performed gene expression profiling of normal and hepatocellular carcinoma (HCC) liver tissues using a high-density microarray that contained 3,063 human cDNA. The results of a microarray hybridization experiment from eight different HCC tissues were analyzed and classified by the Cluster program. Among these differentially-expressed genes, the galectin-3, serine/threonine kinase SGK, translation factor eIF-4A, -4B, -3, fibroblast growth factor receptor, and ribosomal protein L35A were up-regulated; the mRNAs of Nip3, decorin, and the insulin-like growth factor binding protein-3 were down-regulated in HCC. The differential expression of these genes was further confirmed by an RT-PCR analysis. In addition, our data suggest that the gene expression profile of HCC varies according to the histological types.

Carcinoma, Hepatocellular↗